Tvären
58.76565217.414624Koordinaten: 58 ° 45 ' 56 " N, 17 ° 24' 53 " O
Tvären is a circular bay of the Baltic Sea in the municipality of Nyköping the province of Södermanland County near Studsvik in Sweden.
The bay has a diameter of about 4 km and is situated on an old, buried and no longer visible impact crater. The crater has a diameter of about 2 km. Its age is estimated at about 455 million years.
The asteroid ( 7771 ) Tvären is named after the bay.